upslope winter storms along front range of Colorado (Denver, Colorado Springs: tornadoes, to move)

[onthamove]

How does Evergreen fare during these events? I realize denver and the plains can easily top 12'' in a day and sometimes 24'' over a three day period but does evergreen get more since it is higher in elevation? Also another question and this is for Colorado in general why is the average higherst snowfall in the spring months? kinda bizzare but nonetheless cool

[jazzlover]

Evergreen can get big snow in an upslope weather event, it just depends on the track of the storm. As to the spring snowfall peak, it's geography. Most of the early winter storms come out of the northwest. These tend to be drier and the moisture must lift over the Cascades and Sierras before getting to Colorado. In later winter and early spring, the storms tend to come more from the south or southwest. Depending on the track, they can fetch moisture from the Gulf of California or the southern Pacific coast region. Because the atmosphere is somewhat warmer in spring, it can carry more moisture and moisture from the southern part of California has a shorter distance to go to get to Colorado, especially the southern mountains. By spring, more storms can fetch moisture from the Gulf of Mexico. These can be the upslope storms that you mentioned that bring huge snow to the Eastern Slope of Colorado. These can set up in winter, too (and when they do they can be severe), but they tend to be more common in spring. The "perfect storm" for snow production is a low pressure system big enough to tap both Pacific and Gulf moisture (and with relatively warm air to hold a lot of moisture) that meets up with a cold front coming from the north. If the low pressure system moves slowly east along the Colorado/New Mexico border (often called a "Trinidad Low" because it will often pass right over Trinidad, Colorado), it can produce a huge Front Range storm with blizzarding on the Eastern Plains. If the low tracks a little farther north, Cheyenne, Wyoming gets slammed; a little farther south and the Texas Panhandle gets hammered.

The distance from Colorado from moisture sources and the variability of the storm track also means that Colorado is prone to frequent and sometimes severe droughts. Some years the storms just "miss" parts or all of the state. Disturbingly, much of the growth that has occurred in Colorado has occurred during a period (from about the late 1950's to the mid-to late 1980's) with more years with above normal precipitation than those with less. Since then, the opposite has been true. If that trend continues (and some experts believe that Colorado may be in the beginnings of a multi-decade drought period), there just might not be enough water to support the state's current (not to mention future) population. That's pretty scary.

By the way, the convergence of Gulf moisture and cold air that can bring big spring snows to the Front Range can often, at the same time, be the event that triggers severe spring thunderstorms and tornadoes on the Great Plains. Denver can be getting a severe spring snowstorm while eastern Kansas has severe thunderstorms and tornadoes ravaging them. Spring is no calm, pretty season in this region.

[onthamove]

wow tornadoes and blizzards together sounds like Colorado

[Noahma]

Originally Posted by onthamove

wow tornadoes and blizzards together sounds like Colorado

exactly, you forgot 80* weather on the same day, with a little downpour in the eve.


the last big upslope snowstorm we had, was a couple years ago. left 4' of snow on the mountains just west of Evergreen, my grandmother was snowed in for a few days. fortunatly, they are rare,

[Charles]

Originally Posted by jazzlover

These can set up in winter, too (and when they do they can be severe), but they tend to be more common in spring. The "perfect storm" for snow production is a low pressure system big enough to tap both Pacific and Gulf moisture (and with relatively warm air to hold a lot of moisture) that meets up with a cold front coming from the north. If the low pressure system moves slowly east along the Colorado/New Mexico border (often called a "Trinidad Low" because it will often pass right over Trinidad, Colorado), it can produce a huge Front Range storm with blizzarding on the Eastern Plains.

So this sounds like what we got on Dec 21 that shut down DEN. That was one very scary storm. Took me three hours to go 38 miles from Schriever AFB to Monument. Trinidad Lows are also called Albuquerque Lows or are they different?

[BillRadio]

Originally Posted by onthamove

How does Evergreen fare during these events?

While Evergreen and similar foothill communities seem to get more snow during a normal upslope, it isn't the big deal you'd think it is. When Denver gets 12" and Evergreen gets 24", Evergreen residents can still get around...Denver's can't. Jefferson County is prepared to move a lot of snow.

The big differences occur in the "shoulder" months, Sept/Oct & Mar/Apr when Evergreen gets snow and Denver doesn't, due to the lower temperature at altitude. However, Denver is just as likely to get a big dump, and the foothills get nothing.

These big snows you hear in the media really are rare events. I'll trade a 4-foot snow every few years, for a whole winter of clouds & snow cover in the Midwest, anytime.

[onthamove]

not to mention the state of colorado is much more natural beaty than any midwestern area

[jazzlover]

Trinidad lows and Albuquerque lows generally start out in the same area (around the Gulf of California) and move easterly. Albuquerque lows (as the name would indicate) track farther south than a Trinidad low. An Albuquerque low can cause heavy snow around Raton Pass and on into eastern New Mexico and the Texas Panhandle. If an Albuquerque low is strong enough, it can bring significant snow as far north as Colorado Springs, but usually will leave Denver relatively unscathed.

A good book to read to find out about western weather phenonmenons is "Weather Extremes of the West" by Tye Parzybok.